Doing performance mods to a motor with 93,000 miles is a "No, no."
You are increasing the power output of a motor that can barely make the power it was designed to make.
As for the "Skateboard wheel" sound, that is probably a rod bearing. But it could also be a camshaft bearing or lifter.
Checking compression on all cylinders may eliminate the camshaft/lifters (But not always).
Fluctuating oil pressure would indicate a spun rod/main bearing (But not always).
The only sure fire way to locate the source of you noise is to tear the engine down.
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Saturday, January 9th, 2010 AT 9:24 AM